Method of making plates for multicolor printing



, 1,642,451 p 13, F. LIBBY METHOD OF MAKING PLATES FOR MULTICQLOR PRINTING Filed Oct. 30, 1926 INVE'NTOR. Qflwvnk/ f ATTO NEYS.

Patented Sept. 13, 1927.

"UNITED STATES FRANK LIBBYQ r nos AnGELEs', oamroitnm.

METHOD or MAKING PLATES ron UL'rrcoLon PRINTING.

Application'lfiled' October 30, 1926. Serial No. 145,186.

This invention relates to methods of making multi-color prints, and an important object of the invention is to materially lower the cost of color reproduct-ion I According to one I or; the Lpresentday methods in multi-color reproduction, separate half-tones or etchings aremade of the picture that is tobe reproduced, and the engraver works upon eachfplateby removing portions of its surface, thus producing a difierent plate for each of the colors in which the reproduction is to be rendered. Thus, it there are to'be three. colors in the finished print, the engraver prepares three plates. The engraver receives relatively high wages and the preparation'of theplates by him in this manner,consumes considerable time, thus making the old method very expensive.

- By another method, at present employed,

the operations are purely mechanical and color screens are employed. This latter method is also very'ex pensive.

' By this new method, the expense of pro ducing each color plate is no greater than is the expense of making an etching from an ordinary line drawing; In fact, the

operation for making the individual plates is the same, the invention lying in the difference of treatment of the drawings from I which the plates are made.

By this new method the color-separation is provided for by the artist, who prepares a series of handmade drawings, one drawing for each color. 1

The accompanying drawings illustrate the results of certain of the operations per-' formed by the artist.

Figures 1, 2'and 3 are tacsimilesot the artists drawings for effecting color-separa tion. v7i "The new method is performed'astollowsi A drawing is made by the artist and this drawing may be the original drawing. This drawing is made either in an eradicable medium as, for example, pencil, or in .a color having no material actinic e-ttect upon a photographic plate exposed thereto. In either event, the drawing thus made may be used for one of theefinished color-separation drawings. For example, this drawing may be, what I shallterm the blue draw-.

ing, illustrated in Figure 1, since'it may be the one from which the color plate for printing in blue may be made. The artist applies ink lines toithis pencil drawing, onlyv on thoseportions which are to bereproduced in'blue. The ink lines of this drawing are made at an'approximately definite angle or angles. For e-xample,tor the lighter shades, the artist has employed horizontal llnes 4-, and these lines may be placed at different intervals and maybe made'ot varying thicknesses in order to produce the desired shadings. Still heavier shades are securedby ink lines 5 crossing the lines 1 substantially atright-angles, and, in this instance, the lines 5 are substantially vertical. The llnes 4t, 5 will be drawn only upon those areas that are to be reproduced in blue or in a tint in which blue is present.

Where a shade of; maximum depth" is de s red, the ink will be'applied solidly, as indicated at 6. I It will thus be seen that I am able to produce any shade of blue that I may wish for any part of the picture, from the most delicate shade to the solid blue color. 1

. After the blue drawing is completed, the artist places over it a tracingmedium, such, for example, as tracing paper, tracing cloth or celluloid, on which the artist makes a 1 second color separation drawing. Assuma ing, for example, that this second drawing is to be used in making the plate for print ing red, it may be termed the red drawing; The artist proceeds to draw in ink lines over those portions that are to be reproduced in red or in a tint in which red is present. Where a red color is desired in the printed. reproduction, the ink lines will be drawn upon areas of the tracing medium that do not overlie the ink line areas of the blue drawing, but where a tint produced-by blending red and blue is desired, the ink lines will bedrawn uponisome portion of the area of the tracing medium lying over the inkline area of the blue drawing.

For example, referring to Figure 2, the ink lines 7 are placed'at a different angle than the ink lines in Figure 1. These lines, 7

ink applied aolidly, an indifiated at ll, in order to secure a maxinuun depth of the color in the finished reproduction.

It the printed reproduction is to be rendered in three color-a, inl; lines on the red drawing may also be drawn on those per tions oil the tracing medium that are to be reproduced in atint in which red and the third color are present.

\Vhere the printed reprodiu'tion is to appea r in only two colors, no further d rawingrs need be prepared but, in this instance, t is assumed for example, that it desired to have the finished remioduction appear in three colors. Accordingly, the artist will remove the completed red drawhu; from over the blue drawirre; and replace it w'th a tracing medium, of the character mentioned above, and the artist will apply ink lines 10, as indicated in. Figure 3, to those parts ol" the drawing that are to appear in the tin .ished reproduction in a third color or in a tint in which. blue OlT/illltl red are present with the third color. For example, it may be assumed that this third drawing is to be used for making the plate for printing the color yellow. 1 will, accordingly, term it the yellow drawing. The lines are placed at a dilli'erent angle to the horizontal than the lines l, 5, 6 and 7. The. lines 10 may be, ilor example,approximately degrees from the horizontal and the thickness of said lines will be varied, and they will be placed at varyingintervals to obtain the desired shadesf Deeper shades will be secured by the artist. applying ink lines ll, crossing the lines 10 at approximately an angle oil J0 do erees. This drawing, also, has the ink applied solidly, as indicated at 12, to secure the deepestshade of yellow.

ll'here a yellow color is desired in the printed reproduction, the inlelines will be i'lrawn upon areal-.1 oi? the third tracing medium that do not correepond to the int: line areas of the blue and red drawings. ll hcre a tint, moduced by blending 01'' blue and yellow, is desired, the ink lines will be drawn upon some portion of the area ot the third tracing; medium UOll'QSlH)11(llll; f to the ink line area oil the blue drawing. Where a. tint, produced by blending of red and yeh low, is desired, the hilt linee will be drawn upon some portion of the area of the third. tracing medium corresponding: to the inl; line area of the red drawing, Also, when a tint, produced by blending of. blue, red and yellow, is desired, the ink lines will be drawn upon some portion oi the area of the third tracing medium correspendings to the ink line areas ot the blue and red drawings.

If it were desired to make the reproduction in tour colors, the procedure would be the same as above described, excepting that the anglebetween thelines on the different drawings would be approximately 22% de gices instead of 30 degr and a fourth drawing would be made after the manner in which the third drawing was made except.- ing for the areas covered by the lines and the angle of said lines.

In order to facilitate drawing the lines in each drawing at approximately the angle selected for that particular drawing, I may, before proceeding with the drawing oi: the in]: lines, draw upon the tracing medium several guide lines, indicated in thcdrawing by dotted lines These lines are drawn with a suitable protractor or draftsnians angle so that they will extend accurately at the angle selected.

It is to be understood, howevm', that the lines drawn by hand by the artist need only ap n'oximate the angle of the guide lines 123. In fact, slight variations from said. angle will produce the desired artistic ell'ect,. as results from free-hand work distinguishing: from mechanically produced lines.

It the first drawing has been made with pencil or other eradicable medium, the pen cil or other eradicable marlts will be erased or otherwise eradicated.

The nextoperation in this new method is to make, from the different drawings thus completed, photo-etchings or photoanechaie ical printing plates, as they are sometimes termed, in a manner well undm'stoodin the art relating thereto. There will thus be produced a plate for prinitng blue, a plate .tor printing red and a plate :lor. printing; ye low and these plates will be )rinted in that order. 'l hus, not only willtlie printed reprmluction have in it the three primary colors, blue, red and yellow, but it may also hare in it any desired number o'l tints that. would result from mixing the primary colors in various proportions, since the artiat', in client, obtains the tints by varying: the spacing, thickness and arrangement of the ml: lines in the drawings, said. lines being accurately reproducedincolor by the etched plates.

lfre'ferably, the photo-etchings of the draudngs will be made on a single plate so that they will appear on the plate upon exactly the same scale. and the plate will then he cut to separate the photo-etchings for printing. In this way perfect registration is facilitated. L

From the foregoing itwill readily be seen that there is no expensive alteration o'l. plates as required by one of the old proccases, and that the color reproduction has the artistic qualities of freehand drawing which cannot be said for the old processes that employ color screens.

That this new method is far more economical than any of the 01d multi-color processes, can be appreciated tfrom the fact that the drawings made by the artist in this method are all simple line-drawings iou and the etchings are produced from said drawings at from one-third to one-fifth of the cost of the multi-color plates produced by the old methods now in use. For example, by'photo-engraving the three plates of a three-color picture, as a single plate and separating them afterwards, the zinc plates can be produced for a small picture for approximately M00, whereas, by the old methods now in use, multi-color plates for the same sized picture, would cost from $20.00 to $50.00, depending upon whether the plates are made with the so-termed process plates or are made with Benday and color-separation.

By my new method, color reproduction can be made with as great a variety of tones and colors as by any method now in use,

and, at the same time, the color reproduction by my method has a new, unusual, characteristic and attractive appearance.

Because of the freehand drawing done by the artist without the use of any me chanical means or screens, there is a freedom about the appearance of the reproduc tions produced by my method that gives them an artistic appearance.

A great advantage of my method is that it makes possible the use of multi-color printing in a large number of instances where, by the older methods now in vogue,

the cost would be prohibitive.

Because or the artist being guided by the drawing showing through the tracing medium, the drawings for the different colors can be made in but little more time than is necessary for completing the original h'awing. V

As an aid in making the drawings for the different colors, the artist may first outline in pencil the different areas over which he intends applying ink lines. It is to be'understood that the ink lines are applied with pen, and that where the ink is applied solidly, it may be done by the pen or'a suitable brush.

I claim:

1. The method of making plates formulti-color printing consisting in making a plurality of free-hand drawings with ink lines, corresponding areas of the drawings having the lines positioned at a materially different angle when the drawings are superposed, and making photo etchings of said drawings.

2. The method of making plates for multi-color printing consisting in making a t1-color printing consistlng 1n maklng a plurality of free-hand drawings with ink lines varying 1n spacing, corresponding areas of the drawings having the lines positioned at a materially diiferent angle when the drawings are superposed, and making photo-etchings of said drawings.

4. The method of making plates for multi-color printing consisting in making a free-hand drawing with an eradicable medium of the subject that is to be reproduced, drawing ink lines upon that area of the drawing that is to be reproduced in one of the primary colors or in a tint in which said primary color is present, placing a tracing medium over said drawing, drawing ink lines upon some portion of the area of the tracing medium lying over the first-mentioned area and at a materially different angle to the first-mentioned lines, eradicating the eradicable medium from the first-- mentioned drawing, and making photoetchmgs of the respective drawings.

a 5. The method of making plates for multi-color printing consisting in making a' free-hand drawing in a color'having no material actinic effect upon a photographic plate exposed thereto, drawing ink lines upon that area of the drawing that is to be reproduced in one of the primary colors or in a tint in which said primary color is present, placing a tracing medium over said drawing, drawing ink lines upon some portion of the area of the tracing medium lying over the first-mentioned area and at a materially difierent angle to the first-mew tioned lines, and making photo-etchings oi the respective drawings.

6. The method of making plates for multi-color printing consisting in making a plurality of free hand drawings with ink lines, corresponding areas of the drawings having the lines positioned at a materially different angle when the drawings are superposed, making photo-etchings of said drawings on a single plate, and cutting the plate to separate the photo-etchings.

Signed at Los Angeles, Cal, this 19 day of October, 1926.

FRANK LIBBYv 

